// 简单地 DFS
#include "include/tree.hpp"

class Solution {
public:
    TreeNode* mergeTrees(TreeNode* root1, TreeNode* root2) {
        if(root1 == nullptr) return root2;
        if(root2 == nullptr) return root1;
        root1->val += root2->val;
        root1->left = mergeTrees(root1->left,root2->left);
        root1->right = mergeTrees(root1->right, root2->right);
        return root1;
    }
};
